Local onion growers have something to cry about this summer. Tiny, yellow-headed flies called allium leafminers are infesting onion, garlic, shallot and other allium crops in Pennsylvania. Alliums are part of a family of bulbous plants that also include chives and leeks… Rick Van Vranken, Rutgers University agricultural agent for Atlantic County, said the suspicious infestation was found in Mercer County. He said he’s concerned about the parts of Atlantic, Cumberland and Salem counties surrounding the city of Vineland, where more than 25 farmers grow between 10 and 50 acres of leeks and scallions. “If this thing finds its way into these areas, we’re going to have some significant problems,” he said. “It’s worrisome.”